The use of ultraviolet radiation for curing inks, coatings, adhesives and other types of compounds is well known in the prior art. Generally, the frequency of the ultraviolet radiation needed to facilitate the desired curing is dependent upon the particular chemistry of the compound being cured. In recognition of the many advantages attendant to the use of ultraviolet curing, various prior art ultraviolet curing systems have been developed for use in applications such as medical adhesive bonding, electronic assembly, conformal coating rework, wire tacking, potting and sealing, fiberoptic splicing, glass and crystal bonding, and stereo lithography.
One prior art ultraviolet curing system which is representative of many such systems currently available in the marketplace is manufactured by the Applicant and sold under the trade name "Super Spot". This particular device generally comprises a housing which is adapted to be placed upon a support surface such as a counter top and includes a mercury lamp disposed therewithin for providing a source of ultraviolet light. Also disposed within the housing is a power supply which is electrically interfaced to the mercury lamp and to a fan which is attached to the housing and adapted to circulate air therethrough to cool the lamp during its operation. Releasably attached to the housing is one end of an elongate, flexible wand which is liquid filled and adapted to transmit the ultraviolet light from the light source to an ultraviolet curable compound proximate the distal end of the wand. In the wand, liquid is used as the ultraviolet transmission medium since other transmission mediums such as optical fibers are less efficient.
Disposed between the mercury lamp and the end of the wand attached to the housing is a mechanical shutter mechanism which is selectively actuatable between open and closed positions by a solenoid which is mechanically coupled thereto and electrically interfaced to the power supply. The actuation of the shutter mechanism to the open position facilitates the transmission of ultraviolet light from the lamp into the wand, while the actuation of the shutter mechanism to the closed position blocks such transmission.
Though this system and others similar thereto are generally sufficient for exposing an ultraviolet curable compound to ultraviolet light for purposes of curing the compound, these systems possess certain deficiencies which detract from their overall utility. Once such deficiency relates to the use of the mechanical shutter mechanism to block the transmission of ultraviolet light from the light source into the wand when ultraviolet curing is not desired. In this respect, since the shutter mechanism is disposed directly in the light path, it is subjected to extreme temperature fluctuations, i.e. heating and cooling, when the system is in use. This repeated heating and cooling results in failure of the shutter mechanism thus necessitating the repair and/or replacement thereof on a frequent basis. Additionally, the liquid filled wand used with the system is expensive and may only be of limited length due to the loss of energy which occurs as the ultraviolet light travels through the wand. In this respect, since a certain ultraviolet light intensity level is typically needed to facilitate the desired curing of the compound, the length of the wand must be limited so that the losses caused by the transmission of the ultraviolet light therethrough do not result in a light intensity output which is below the level needed to achieve the desired curing. Thus, the housing of the curing system must usually be maintained in close proximity to the work piece upon which the curing operation is being conducted. The present invention overcomes these and other deficiencies associated with prior art ultraviolet curing systems.